How long a KZ can stay if they travel alone?

Generally, he will be granted a tourist L with duration of 30 days. If he will stay in your place, you need to include this information in the letter, with detailed address and your information. House property certificate is not required, but make sure send him copies of your Chinese ID.

Thank you very much for your answear. It is very helpful. I also want to know if he needs show the proof of his founds that can make sure he has enough money to travel here (Even he won't cost too much money if he will live in my house)? What if I want to provide him the money for travel, can I mention this point in my invitation later and show my proof of founds ? At the same time, do I need show my job certificate? ( Sorry that my question is too much)

If you will sponsor the trip, provide your bank certificate, and invitation letter with details. Job certificate is not necessary.

Brilliant! Thank you very much again! Last Question: How long it will take to get the tourist L by paying the regular fee?

Regular processing time needed is 4 working days.